First it was Japan's steel makers, now it's the nation's power producers that are set to pay for China's coal policies.

Japanese utilities may pay at least 29 percent more for annual supplies this year after China's efforts in 2016 to trim overcapacity led to a more than doubling of spot prices, according to UBS Group AG and Morgan Stanley.

Contract talks have begun with coal miners Glencore PLC and Rio Tinto Group, according to a spokesman from Tohoku Electric Power Co., which typically negotiates the deal on behalf of the nation's electricity providers.